Device for controlling the tension when winding material



D. HANK May 2, 1967 DEVICE FOR CONTROLLING THE TENSION WHEN WINDING MATERIAL Filed Aug. 20, 1965 United States Patent 3,317,156 DEVICE FOR CONTROLLING THE TENSION WHEN WINDING MATERIAL Dietrich Hank, Leipzig, Germany, assignor to VEB Druckmaschinenwerke Leipzig, Leipzig, Germany Filed Aug. 20, 1965, Ser. No. 481,268 6. Claims. (Cl. 242--75.3)

The invention relates to a device for controlling tension when winding material by means of a compensating roller.

When winding material, such as paper, whereby a winding differential of for instance, 1:4 is required, it is essential to control the tension of the material in order to obtain a smoothly rwound take-up and storage roll. When the diameter of the take-up and storage roll to be coiled increases, the tension applied to the roll has to beduced. The tension should, therefore, not increase while the diameter of the take-up and storage roll increases, because this would lead to slippage of already coiled material due to the higher torque. The change in tension of the material depends upon the initial tension applied and on the friction between the different windings.

It has been noted that different types of material require a different tension, depending on the winding ratio. For obtaining the characteristic material tension it is known to employ a compensating roller whose effective mass is balanced by an adjustable counter weight:

Devices are known in which a movable roll is connected by means of a balancing lever system to an adjustable gravity controlled element, consisting of a longitudin-al container partly filled with a liquid medium. When the diameter of the take-up and storage roll increases, the location of the compensating roller with the balancing lever system and the angular position of the container also changes. At the same time, a speed regulator is actuated which reduces the speed of the motor of the take-up and storage roll. A change of the angular position of the container causes some of the liquid medium to be withdrawn, resulting in a reduction of the tension in the material.

In these known devices the location of the compensating roll serves as a measure for the diameter of the takeup and storage roll. This type of measurement, however, is rather inaccurate since speed ditferentials change the location of the compensating roll which leads to an increase or a reduction respectively of material tension. The result is a fluctuation of the liquid medium and consequently a difference in the tension in the material. Since the location of the compensating roll serves as a measure for the take-up and storage roll diameter, the possible winding of the material is rather limited.

A further disadvantage of these devices is that the compensating roll is connected to a lever, lwhereby with the change of location of the compensating roll, a paper material is pulled at an angle instead of vertically. The result is a change of the applied tension and subsequently an undesired tension ditferential.

These devices are, therefore, only suitable for slowly movable material and for rolls with a relatively small take-up and storage roll diameter.

It is, therefore, an object of the invention to provide a device for regulating the material tension which is especially adapted for relatively large diameters of takeup and storage rolls as well as for relative high and constant material speed, when employing the compensating roll. It is important that the material tension changes corresponding to the ratio of the coiled material independently of the location and the motion of the compensating roll.

According to the invention a compensating roller is connected directly with a container partly filled with a liquid medium. The contents of the container is changeable with the assistance of a volume changing cylinder through a flexible tube depending from the changing diameter of the take-up and storage roll during the winding process. The volume changing cylinder is connected through a mechanical system with a scanning shaft which scans the roll. The tension of the material during the winding process is defined by a corrective member.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and the specific objects obtained by its use, reference should be made to the accompanying drawings and descriptive matter in which:

FIG. 1 is a schematic showing of an embodiment of the invention in side view at the beginning of the winding procedure; and

FIG. 2 shows the embodiment of the invention according to FIG. 1 at the end of the winding process.

Referring now to the figures, FIG. 1 shows a take-up and storage roll 15 which receives a band of material 1 from a machine (not shown). The material 1 is guided about two guiding rolls 16 and 17 forming a loop in which a trailing compensating roll 2 is located. Roll 2 is mounted onto a securing means 3 disposed between container 4 and roll 2. Connected to the roll 2 is a freely swinging container 4 partly filled With a liquid medium 5. A flexible tube 6 connects the container with a stationary volume changing cylinder 7. In contrast to the container 4, which can be open towards the top, the cylinder 7 is tightly closed. The position of the container 4 is thereby independent of the position of the cylinder 7. A counterweight 8 is arranged above cylinder 7, exerting a sufiicient amount of pressure thereon. A connecting link 9 guided over roll 10 connects cylinder 7 with a lever 13. A corrective member 11, which could be replaced for instance by a cam, is adjustably mounted at lever 13, where it can be held in fixed position. The lever 13 carries a roll 14 and is pivotably mounted on a bearing 12. At the beginning of the winding process as seen in FIG. 1 a predetermined amount of the liquid medium 5 is present in the container 4 and defines, together with the mass of the compensating roll 2, the initial tension of the material. When the diameter of the take-up and storage roll 15 increases, as shown in FIG. 2, the cylinder 7 is actuated by the change of location of the roll 14, lever 13 and member 11 so that part of the liquid part medium 5 is continuously drawn out of the container 4 whereby the tension in the material is reduced.

Corrective member 11 insures that the liquid medium is not removed in an even ratio from the container 4, but in a predetermined ratio corresponding to the diameter of the take-up storage roll 15. This is essential in order to obtain a certain tension for a certain kind of material.

This invention should not, however, be limited to the specific embodiment disclosed, but rather should be defined by the scope of the appended claims.

What is claimed is:

1. A device for regulating tension on a fibrous material during the operation of winding said material upon a storage roller comprising:

(a) a variable volume cylinder,

(b) means for sensing the diameter of said fibrous material on said storage roll,

(0) means for varying the volume of said cylinder,

(d) mechanical linkage connecting said sensing means to said volume varying means,

(e) a container for containing a liquid therein; and

(f) a flexible conduit connecting said container to said variable volume cylinder.

2. A device as in claim 1, wherein said sensing means comprises a roller which rests upon the outer periphery of said storage roller.

3. A device as in claim 2, wherein said linkage comprises a lever connected at one end thereof to said roller and a wire connecting the other end of said lever to said volume varying means.

4. A device as in claim 1, wherein said volume varying .means comprises a weight connected to said variable volume cylinder.

5. A device as in claim 1, further comprising a compensating roll over Which said fibrous material passes supporting said container in a vertical disposition.

6. A device as in claim 1, further comprising an adjustable member connected to said mechanical linkage for adjusting the tension on said fibrous material.

5 References Cited by the Examiner UNITED STATES PATENTS 2,569,264 9/1951 Stone et a1 24275.3 2,886,257 5/1959 Hill 242--75.5

10 FRANK J. COHEN, Primary Examiner.

STANLEY N. GILREATH, Examiner. N. L. MINTZ, Assistant Examiner. 

1. A DEVICE FOR REGULATING TENSION ON A FIBROUS MATERIAL DURING THE OPERATION OF WINDING SAID MATERIAL UPON A STORAGE ROLLER COMPRISING: (A) A VARIABLE VOLUME CYLINDER, (B) MEANS FOR SENSING THE DIAMETER OF SAID FIBROUS MATERIAL ON SAID STORAGE ROLL, (C) MEANS FOR VARYING THE VOLUME OF SAID CYLINDER, (D) MECHANICAL LINKAGE CONNECTING SAID SENSING MEANS TO SAID VOLUME VARYING MEANS, (E) A CONTAINER FOR CONTAINING A LIQUID THEREIN; AND (F) A FLEXIBLE CONDUIT CONNECTING SAID CONTAINER TO SAID VARIABLE VOLUME CYLINDER. 